The Massachusetts Alzheimer's Disease Research Center (ADRC) is a multi-institutional consortium composed of Harvard-affiliated facilities including the Massachusetts General Hospital, the Brigham and Women's Hospital, the Harvard Division on Aging and the Hebrew Rehabilitation Center for the Aged. The broad goals of the Massachusetts ADRC have evolved from those first proposed in 1984 but remain constant in the mission to prevent, cure or at least treat effectively AD and related dementing diseases. The specific goals are: To propose and support new research in neuroscience directed toward uncovering the etiology and pathogenetic mechanisms of AD and related dementias; to enhance collaborative dementia research funded outside of the ADRC; and to catalyze education, training and information transfer related to AD and related dementias. To accomplish these goals, we will retain the four Core facilities that were established 20 years ago. Investigators in the Clinical Core examine and diagnose patients with AD and related disorders, and refer them for participation in specific research Projects. The purpose of the Neuropathology Core is to establish diagnoses on all brains submitted to the Tissue Resource Center, store fixed and frozen brain tissue and distribute brain tissue to qualified investigators. The Education and Information Transfer Core has developed programs to train future leaders in academic fields related to aging and dementia, to educate caregivers, and to enroll elderly, non-demented control subjects into ADRC research. To these four Cores, we have added a fifth: The Data Management and Statistics Core that will carry on and expand activities that had previously been housed in the Administrative Core. The overriding mission of the ADRC is to stimulate and support research of the highest quality. This application contains three R01-type Projects that are closely inter-related and also tightly linked to the Clinical, Neuropathological and Data Management and Statistics Cores.